Temperature control system



Feb. 4, 1936. DA G. TAYLoR 2,029,513

TEMPERATURE CONTROL SYSTEM Filed Apri1v25, 1955 01 N D m /v m M 'if Syvum/vtm Daniel G., Taylor Patented Feb. 4, 1936 UNITED STATES PATENTY OFFICE TEMPERATURE CONTROL SYSTEM Daniel G. Taylor, Minneapolis, Minn., assigner to Minneapolis-Honeywell Regulator Company,

13 Claims.

` 512,887, tiled February 2, 1931.

This system disclosed in the above identified application is directed to the maintenance of a normal temperature condition within a building in response to outside atmospheric conditions including temperature, wind and solar radiation. The system comprises a heating means for a building and an outdoor controller responsive to atmospheric conditions. The outdoor controller includes a thermostatic element land heating means. The heating means of the building and of the outdoor controller are under the control of the thermostatic means. Upon a call for heat by the thermostatic means, both heating means are placed in operation and when the temperature within the controller reaches a predetermined value, both heating means are placed out of operation. The heating means of the building and the controller are related to each other in accordance with the heat lossesvfrom the building and the controller so that by maintaining a predetermined temperature Within the controller a predetermined temperature is maintained within the building.

The success of such a system depends upon the fact that proportionate amounts of heat are placed in the building and in the outdoor controller. Such a system works eciently and to good advantage Where an unlimited supply of heating medium is available whether it be from a central heating system or from a boiler which is maintained in a heated condition at all times. However, where the outdoor controller controls the operation of a boiler by means of an oil burner, a Stoker or a gas burner, some time must elapse between the time the heating equipment is placed in operation and the time when steam is actually supplied to the radiators in the building. During this time, heat is being supplied to the outdoor controller and it is readily seen that when this is the state of affairs more heat is supplied to the outdoor controller in proportion to the heat supplied to the building. This causes a break down of the above ratio with a consequent inadequate heating of the building.

It is therefore an object of this invention to remedy this difficulty whereby the above ratio may be maintained and the building properly heated.

More specifically, it is an object of this invention to provide means for preventing energization of the heating -means for the outdoor controller until heat is actually delivered to the building.

titl! 5 nl Still more specically, it is an object of this invention to provide means for preventing energization of the controller heating means until steam is actually being supplied to the heat eX- changer means in the building.

Another object is to provide a condition responsive means for maintaining the temperature of the water in the boiler at a predetermined minimum value, to reduce the time lag between the time of calling for heat by the outdoor controller and the time at which heat is actually delivered to the building.

Still another object is to provide means for preventing overheating of the boiler in the above type of temperature changing system.

Other objects and advantages will become apparent to those skilled in the art by reference to the accompanying specification, claims and drawing in which. drawing, there is diagrammatically shown the p f ferred form of my invention.

A building s diagrammatically shown having a side wall I and spaces to be heated II. In one of the spaces to be heated II is shown a radiator I 2 which receives its supply of heating fluid from a riser I3 which is in turn connected to a header I4 leading from Va boiler I5. The boiler I5 is red by means of an oil burner I6 having a control box II containing the usual safety switches and other mechanism relation thereto. Upon operation of the oil burner I6, steam is generated in the boiler I and delivered through the headers I4 and risers I3 to the various radiators I2 located" in the spaces to be heated.

Located outside of the building and responsive toI atmospheric conditions such as temperature, Wind and solar radiation is an outdoor controller I8. The controller I8 comprises a metallic block I9 which is enclosed in a weather-tight housing 20. The metallic block I9 is hollowed out to receive a casing 2| which in turn contains a blmetallic member 22 mounted on a post 23. The bimetallic member responds to the temperature of the metallic block I9. The bimetallic member carries contacts 24 and 25 which are adapted to sequentially engage stationary contacts 26 and 21. Contacts 26 and 21 are made adjustable so that the proper operating diierentials may be maintained. The block I9 is heated by means of a heater 28 at predetermined times in a manner to be pointed out more specifically hereafter and cooled by outdoor atmospheric conditions.

vA condition responsive device 30 responds to the condition of the building heating system. It may comprise either a pressure or temperature responsive device for operating a mercury switch 3|. Such a structure is old in the art and a further detailed description thereof is not considered necessary. The mercury switch 3| is maintained in an open position until steam passes through the header I4 at which time the4 mercury switch 3| will be shifted to a closed position either by the temperature of the steam or by the pressure of the steam. Preferably, the condition responsive device 30 is located as far away from the boiler as is possible so that it will respond to the existence of steam just as the steam is about to enter the radiators I2.

Located on the boiler I5 is a low limit temperature controller 32 responsive to the temperature of the boiler water to operate a mercury switch 33. The mercury switch 33 is maintained in a closed position when the temperature of the boiler water is below a predetermined minimum and when the temperature of the water is above this predetermined minimum, the mercury switch 33 is tilted to circuit opened position. Also located on the boiler I 5 is a high limit temperature or pressure controller 34 for operating a mercury switch 35. When the temperature or pressure in the boiler' I5 is below a predetermined maximum value, the switch 35 is maintained in a circuit closed position but when the pressure or temperature. becomes abnormally high, the mercury switch 35 is tilted to a circuit open position.

Located at some convenient point in the basement of the building is a basement switch 36 adapted to alternately engage an Uon contact 31 or an automatic contact 38.

Line wires 40 and 4| lead from some source of power, not shown. Wires 42 and 43 connect a primary 44 of a step-down transformer 45 across the line wires 40 and 4|, respectively. The stepdown transformer 45 has a secondary 46.

A relay coil is designated at 41 and operates switch arms 48, 49 and 50. Upon energization of the relay 41, the switch arms 48, 49 and 50 are brought into engagement with contacts 5|, 52 and 53, respectively, and upon deenergization of the relay coil 41, the switch arms are moved out of engagement with the contacts by means of springs, gravity or other means, not shown. One end of the secondary 46 is connected by means of a wire 54 to the post 23 supporting the bimetallic member 22 in the outdoor controller I8. The. contact 26 of the outdoor controller` is connected by means of a wire 55 to the contact 5| of the relay swtich. The contact 21 of the outside controller is connected by means of a wire 56 and a wire 51 to one end of the relay coil 41. The other end of the relay coil 41 is connected by means of a wire 58 to the other ef'id of the secondary 46 of the step-down transformer 45. The switch arm 48 is connected by means of a wire 59 to the junction of wires 56 and 51.

When the temperature of the block I9 decreases to a predetermined Value, contact 24 is moved into engagement with contact 26 and upon a further decrease in temperature, the contact 25 moves into engagement with contact 21 to complete a circuit from the secondary 46 of the step-down transformer 45 through wire 54, bimetallic element 22, contacts 25 and 21, Wire 56, wire 51, relay coil 41 and wire 58 back to the secondary 46. Completion of this circuit causes energization of the relay coil 41 to move the switch arms 48, 49 and 5U into engagement with the contacts 5|, 52 and 53. Upon pulling in of the relay, a second or holding circuit is completed from the secondary 46 of the step-down transformer 45 through wire 54, bimetallic element 22, contacts 24 and 26, wire 55, contact 5|, switch arm 48, wires 59 and 51, relay coil 41 and wire 58 back to the secondary 46. This holding circuit will remain energized until an increase in temperature of the block I9 causes the contact 24 to disengage the contact 26 whereupon the relay will fall out.

The line wire 40 is connected by means of wires 60 and 6| to the contact 52. The switch arm 49 is connected by means of wires 62 and 63 to the automatic contact 38. The switch arm 36 is in turn connected by means of a wire 64 to one electrode of the high limit mercury switch 35. The other electrode thereof is connected by means of wires 69 and 65 to the control box I1 of the oil burner I6 and the control box I1 is in turn connected by means of wires 66 and 61 to the line wire 4|. Upon energization of the relay in the above described manner, switch arm 49 is brought into engagement with the contact 52 to complete a circuit from the line wire 40 through wires 60 and 6I, contact 52. switch arm 49, wires 62 and 63, automatic contact 38, switch arm 36, wire 64, mercury switch 35, wires 69 and 65, oil burner I6 and wires 66 and 61 back to the line wire 4|. The completion of this circuit causes energization of the oil burner I6 with consequent generation of steam within the boiler I 5 and delivery of st-eam to the radiators I2 in the spaces to be heated.

Contact 53 is connected by means of a wire 68 to the junction of wires and 69. The switch arm 50 is connected by means of a wire 10 to a variable resistance 1I which is in turn connected by means of a wire 12 to an ammeter 13. The ammeter 13 is connected by means of a wire 14 to one electrode of the mercury switch 3| and the other electrode of the mercury switch 3| is connected by means of wire 15 to the heater 28.

The heater 28 is in turn connected by means of a wire 16 to the junction of wires 66 and 61. Upon energization of the relay coil 41 in the above described manner, switch arms 49 and 50 are moved into engagement with the contacts 52 and 53 to complete a circuit from line wire 40, through wires 60 and 6|, contact 52. switch arm 49, wires 62 and 63, automatic contact 38. switch arm 36. wire 64, mercury switch 35. wires 69 and 68, contact 53, switch arm 5U, wire 10, variable resistance 1|. wire 12, ammeter 13, wire 14. mercury switch 3|, wire 15, heater 28 and wires 16 and 61 back to the line wire 4|.` Upon completion of this circuit. the heater 28 is placed in operation to cause heating of the metallic f block I 9. 'Ihe amount of heat delivered to the heater 28 may be determined and visually indicated by means of the variable resistance 1| and ammeter 13 to place the correct proportion of heat into the outdoor controller with respect to the heat placed in the building in order to maintain an eflicient and satisfactory operation of the heating system.

Due to the fact that the mercury switch 3| responsive to the temperature or pressure within the header I4 is in series with the heater 28, the heater 28 cannot be energized until steam has actually been generated in the boiler I5 and delivered to the radiators I2 in the spaces to be heated II. In' this manner, the proportionate amounts of heat delivered to the building and to the outdoor controller may be maintained regardless of the time lag that must necessarily exist between the energization of the oil burner I6 and the delivery of heat to the spaces to be heated.

Wires 'I'I and 18 are connected between the junction of wires 60 and 6I and one electrode of the mercury switch 33 of the low limit controller 32. The other electrode of the mercury switch 33 is connected by means of a Wire I9 to the' junction of wires 62 and 63. When the temperature of the water within the boiler I5 falls below a predetermined value, the mercury switch 33 is tilted to closed position to complete a circuit from the line wire 40 through wires 60, Il and 18, mercury switch 33, wires 'I9 and 63, automatic contact 38, switch arm 36, wire 64, mercury switch`35, wire 69, wire 65, oil burner I6, Wire 66 and wire 61 backto the line wire 4I to cause energization of the oil burner I6 regardless of whether the relay is opened or closed.. In this manner, the temperature of the boiler water is maintained at a temperature just below the steaming point whereby the time lag between the time that the oil burner I6 is normally placed in operation by the closing of the relay and the time that steam is delivered to the radiators I2 in the spaces to be heated is materially reduced. This low limit function of the mercury switch 33 smocths out the curve of the heating system and prevents under-shooting of the system.

The on contact 3l is connected by means of a wire 83 to the junction .of wires IT and 'I8 and when the switch arm 36 is moved into engagement with the on contact 31, the oil burner I6 is placed in operation by means of a circuit from the line wire 40 through wires 66, 'I1 and 80, on contact 31, switch arm 36, wire 64, mercury switch 35, wire 69, wire 65, oil burner I6 and wires 66 and 6l back to the line wire lll. In this manner, the oil burner I6 may be manually controlled irrespective of the other controlling circuits.

Since the mercury switch 35 of the high limit controller 34 is in series with both the oil burner I6 and the heater 28 of the outdoor controller I8, abnormally high boiler conditions will prevent operation of the oil burner I6 and the heater 28.

From the above it is seen that when the temperature of the block I9 of the outdoor controller I8 decreases to a predetermined value, the relay coil 4l is energized to close the relay switches to complete circuits for energizing the oil burner and the heater 28. The oil burner is placed in 'operation to generate steam and deliver steam to the radiators I2 to heat the building but the heating element 28 is prevented from being energized by the mercury switch 3| operatedrby the tem` perature or pressure controller 39 until steam has been generated and is actually being delivered to the radiators I2 in the building. By reason of this construction, the proper ratio between the heat losses from the building and the controller and the heat input to the building and the controller may be maintained regardless of the time lag required for steaming the boiler. Also, it is seen that I have provided a means for maintaining the boiler water .tempera-ture above a predetermined minimum whereby the time lag between the iiring of the boiler and the delivery of steam to th-e building is materially reduced whereby under-shooting of the heating system is materially reduced.

Although I have disclosed one specic form of my invention for purposes of i1lustration,`I do not wish to be limited thereby but intend that my invention shall be determined by the scope of the appended claims and the prior art.

I claim as my invention:

1. In a system of the class described, temperature changing means for a building, a. controller responsive to outside atmospheric conditions, temperature changing means for said controller, means responsive to the temperature of said controller for energizing both of said temperature changing means, and means to prevent energization of said controller temperature changing means until said building temperature changing means begins to alect the temperature in the building.

2. In a system of the class described, temperature changing means for a building, a controller responsive to outside atmospheric conditions, temperature changing means for said controller, means responsive to the temperature of said controller for energizing both of said temperature changing means, and means responsive to the condition of the building temperature changing meansto prevent energization of the controller temperature changing means until the building temperature changing means is about to affect the temperature in the building.

3. In a system of the class described, steam heating means for heating a building, a controller responsive to outside atmospheric conditions, heating means for the controller, means responsive to the temperature of the controller for energizing both of said heating means, and means to prevent energization of the controller heating means until the building heating means is about to heat the building.

4. In a system of the class described, heat transfer means for heating a building, means for supplying heat to the heat transfer means, outdoor thez'mostatic means, means for supplying heat to the outdoor thermostatic means, said outdoor thermostatic means controlling both of the heat supplying means, and means for preventing the supplying of heat to the outdoor thermostatic means until heat is supplied to the heat transfer means.

5. In a system of the class described, heat transfer means for heating a building, means for supplying heat to the heat transfer means, outdoor thermostatic means, means for supplying h eat to the outdoor thermostatic means, said outdoor thermostatic means controlling both of the heat supplying means, means for preventing the supplying of heat `to the outdoor thermostatic means until heat is supplied to the heat transfer means, and means for maintaining a predetermined minimum amount of heat in the heat supplying means for the heat transfer means.

6. In a system of the class described. heat transfer means for heating a building, a boiler for supplying steam to the heat transfer means, means for 'heating the boiler, an outdoor controller including heating means and thermestatic means, the thermostatic means controlling the operation of both heating means, and means to prevent operation of the heating means for the controller until steam is supplied to the heat transfer means.

'7. In a system of the class described, heat transfer means for heating a building, a boiler for supplying steam to the heat transfer means, means for heating the boiler, an outdoor controller including heating means and thermostatic means, the thermostatic means controlling the operation of both heating means, means to prevent operation of the heating means for the controller until steam is supplied to the heat transfer means, and means to maintain a predetermined minimum condition in the boiler.

8. In a system of the class described, heat transfer means for heating a building, a boiler for supplying steam to the heat transfer means, means for heating the boiler, an outdoor controller including heating means and thermostatic means, the thermostatic means controlling the operation of both heating means, means to prevent operation of the heating means for the controller until steam is supplied to the heat transfer means, and means to maintain a predetermined minimum temperature in the boiler.

9. In a system of the class described, heat transfer means for heating a. building, a boiler for supplying steam to the heat transfer means, means for heating the boiler, an outdoor controller including heating means and thermostatic means, the thermostatic means controlling the operation of both heating means, means to prevent operation of the heating means for the controller until steam is supplied to the heat transfer means, and means to maintain the condition of the boiler between a predetermined minimum temperature condition and a predetermined maximum pressure condition.

10. In combination with a heating system for a building including heat transfer means, a boiler for supplying steam to the heat transfer means and means for heating the boiler, of an outdoor controller including heating means and 'thermostatic means, the thermostatic means controlling the operation of both heating means, and means responsive to the condition of the heating system boiler, of an outdoor controller including electric heating means and a thermostatic switch, the heating means for the boiler and the controller being connected in parallel and controlled by the thermostatic means, and switching means in series with the controller heating means to prevent operation of the controller heating means until steam is supplied to the heat transfer means.

12. In combination with a heating system for a building including heat transfer means, a boiler for supplying steam to the heat transfer means and electrically controlled means for heating the boiler, of an outdoor controller including electric heating means and a thermostatic switch, the heating means for the boiler and the controller being connected in parallel and controlled by the thermostatic means, switching means in series with the controller heating means to prevent operation of the controller heating means until steam is supplied to the heat transfer means, and switching means in series with the boiler heating means to prevent operation of the boiler heating means in case the condition of the boiler becomes abnormal.

13. In combination with a heating system for a building including heat transfer means, a boiler for supplying steam to the heat transfer means and electrically controlled means for heating the boiler, of an outdoor controller including electric heating means and a thermostatic switch, the heating means for the boiler and the controller being connected in parallel and controlled by the thermostatic means, switching means in series with the controller heating means to prevent operation of the controller heating means until steam is supplied to the heat transfer means, and switching means in parallel with the boiler heating means to maintain the condition of the boiler at a predetermined minimum.

DANIEL G. TAYLOR. 

